Commit: aaa334d67aa21331abf0070ef0f7fd61330ec61a
3 x 2
3 x 2, set limits
3 x 2, just = (0, 0)
1 x 3
1 x 3, set limits
1 x 3, just = (0, 0)
3 x 1
3 x 1, set limits
3 x 1, just = (0, 0)
irregular categorical